The desire for wireless communication and faster communication speeds are considerable and ever increasing. As time goes on, more and more devices from portable computers and portable digital assistants to cellular phones are utilizing and demanding more communication speed and bandwidth. In addition to the number of devices, the amount of data being transferred via wireless communication is also increasing because of the types of data being sent. Communications have advanced from merely transporting voice data to transporting multimedia information, including graphical and video information, which employ greater amounts of information.
One particular type of wireless communication is ultra wide band communication (UWB), which operates at about the 3.1-10.6 GHz range and relies on the principle that a high data-rate communication is achievable at a small transmission power when signal bandwidth is appreciably large. As a result, UWB promises to permit high data rates for less power than at least some conventional wireless communication systems. This characteristic can permit devices to transfer more data while operating with less power, which could extend battery life of devices (e.g., cellular phones, laptop computers, and the like) along with other benefits. Additionally, UWB communication is at such a relatively low power that it can mitigate interference with other types of communication. For example, a UWB transmission could appear as merely white noise to a conventional receiver.
One potential problem or difficulty that can be encountered with substantially all wireless communication technologies, and particularly UWB, is that of multipath signals. Multipath signals are generated when a transmitter sends or broadcasts a signal, generally in all directions, and a number of copies of that signal are received at a receiver. Signals often do not travel in a straight line from a transmitter to a receiver (line of sight), but can often bounce off objects so as to end up at the receiver. The copies occur because the original signal bounces against objects during transmission resulting in the number of copies arriving at the receiver, generally with varying delays. Multipath signals can cause a receiver to misinterpret the information being transmitted and/or introduce erroneous information into communication.
Another potential problem or difficulty that can be encountered with substantially all wireless communication technologies, and particularly UWB, is channel estimate noise. Even if multipath signals are resolved or partially resolved, resultant channel estimates can contain substantial amounts of noise. This noise can lead to data errors and the like.